This invention relates to motion snubbing devices, which are provided between a supporting body and a supported body to permit low acceleration displacements of the two relative to each other while restricting high acceleration displacements caused due to external forces.
Snubbing devices of this sort are used for supporting piping systems in chemical plants, atomic power plants and so forth.
Many proposals regarding this type of device have hitherto been made. These devices are generally required to have functions of permitting slow motion of the supported pipe or the like due to changes of the temperature thereof while restricting high acceleration motion of the pipe that might otherwise be caused when sudden forces such as forces produced at the time of occurrence of an earthquake are exerted to the pipe, thus preventing damage to or rupture of the pipe.
The prior-art devices include a type using an inertia mass. This type of device has a drawback in that if the inertia mass is increased in size for providing sufficient snubbing effects upon motions of accelerations in excess of the permissible range, not only the device is increased in size but also considerable snubbing forces are produced even in the case of motions in the permissible low acceleration range and have adverse effects upon the slow motion of the pipe.
There is another type of device which makes use of a brake. This type of device requires additional component parts such as auxiliary springs for automatically releasing the braking force.